Over the years, many water filtration systems and much of the current technology for interfaces between filter cartridges and manifolds are based around ¼ (quarter) turn bayonet styles. This type of interface tends to result in high removal forces due to the high compression on the sealing components (typically o-rings or other rubber-like types of seals), and the compression sets taken by the rubber-like seals. These ¼ turn devices require both a translational and rotational motion to install and remove the filter cartridge.
Newer styles of interfaces have employed external button release mechanisms. These mechanisms are typically high in force and add extra expense from an increase in components to the overall fluid filtration system. They can also disadvantageously also increase the overall size of the system. Furthermore, like the ¼ turn devices, two different motions are required to install and remove the filter cartridge for an external button system (one translational motion to push the button and one translational motion to move the filter cartridge).
Often, it is desirable to place the filter in a location within a refrigerator or other unit where a rotating filter is not possible. Also, some applications require more than one filter side-by-side, which also prevents a rotating filter cartridge from being feasible.
Linear motion designs for filtration systems have been developed that utilize push-activated lock mechanisms. Although the filter cartridges in these systems can be installed through a linear push-in motion, in order to remove these filter cartridges, the user must first push in the filter cartridge to unlock the mechanism, then pull the cartridge in the opposite direction to remove the filter cartridge from the manifold. Furthermore, these push-activated lock mechanisms are complicated to fabricate and implement, and thus increase the cost and complexity of the filtration system.
There is a need for cartridges and simple filtration systems that provide a filter cartridge which can be easily installed by a straight line push motion and removed through a straight line pull motion.